In a conventional military operation, helicopters, such as the AH-64, are widely utilized and, in remote landing zones, arrive in darkness. The copilot gunner, sitting in the front seat of the helicopter, assists the command pilot, sitting in the rear seat, in landing the aircraft on the proper site by giving him verbal directions. Specifically the copilot gunner utilizes night-vision goggles to view a lighted inverted "y" configuration on the ground which is formed by using chemical sticks or flammable bean bags. The heat emitted by these devices is insufficient for the command pilot, using a conventional pilot night vision system, to view the inverted "Y" because he is sitting in the second or rear seat.
In tactical situations, such as during Desert Storm, in order to generate additional heat, one of the expedients includes filling coffee cans with jet fuel-soaked sand and then setting them on fire. As the helicopters approach the landing zone, the fires are extinguished leaving a heat signature sufficient to be viewed by the command pilot using the pilot night vision system. Clearly this practice is inefficient and even dangerous.